The present invention relates to a method and its apparatus for controlling the filling, under aseptic conditions, of containers such as flasks or vials of pharmaceutical products, intended to contain products that are sterilized, for example, by filtration.
As is known, there are products which by their nature cannot be sterilized by heating, so that sterilization thereof is carried out by filtration. In the processing of these flasks or vials which contain the aforesaid products, what is of special importance is the process of metered filling into the aforesaid containers, which have previously been washed and sterilized so that no particles may enter which could contain pathogenic germs.
For this reason, the flasks and their stoppers are sterilized in an autoclave and the liquid intended for them is sterilized by filtration.
In the customary process, the flasks and their stoppers emerge from the autoclaving step under sterile conditions and the flasks are partially capped. In the metered filling step, a critical stage is entered in which the metering machine removes the lids from the flasks, proceeds to introduce the liquid for each of them individually, and covers them again. Therefore, during the time when the flask is not covered over, there is a risk of contamination occurring, even though the process is carried out under a flow of suitably filtered air.
The method of the present invention relates to the problem mentioned previously, making it possible to identify each flask or vial, relating it precisely to the moment at which it was filled and making it possible to display a posteriori the actual filling step, all this leading to the result that in a hypothetical case of some contamination being discovered once the containers have been marketed, there is a possibility of determining very precisely when the filling of the contaminated container took place, which will make it possible to check the containers immediately preceding and following it, in order to ensure that the contamination has not extended to a larger number of containers, and will likewise make it possible to observe the metered filling step which took place, in order to locate any possible failure which produced the contamination and in this way enable this possible cause of contamination to be corrected.
In order to achieve its objectives, the method of the present invention comprises the combination of: a) an operation of indelible marking, on the glass of the container, of the desired identification data, which customarily comprise the product batch, a sequential filling number, and the hour, minute and second of filling, with b) a recording on magnetic tape, by means of a television camera, of the operation of filling all the units which comprise the product batch, so that the recording is carried out continuously during the operation of the installation, recording the metered filling operation continuously, making it possible a posteriori to relate any flask, identified by the indelibly marked inscriptions, to the work carried out in the installation in the corresponding area of the recording which is kept on magnetic tape, thereby making it possible to study the metered filling step thoroughly in order to locate the cause of the contamination in the event that this has occurred during the filling step.
The timing devices for the marking of the flasks and for the taking of pictures with the television camera are synchronized so that there is precise correspondence in time, making it possible to relate any container to a precise, specific area of the magnetic tape which is retained during the entire expiry period of the product, forming part of the documentation of each batch.
The marking of the glass flasks will be carried out indelibly, for example by means of etching by laser. However, any system of marking, for example by means of special dyes, marks made by products for chemically attacking the glass, or any other, may be used in the execution of the method of the invention, provided that they are totally indelible.